The kinematic coupling of two devices of the above type is generally realised by using an intermediate coupling body between the two devices, in which the ends of the drive shaft and the driven shaft are positioned.
The end of the drive shaft is generally provided with grooved means, able to insert in complementary grooved means in the hollow end of the driven shaft.
In the present description the grooved means comprise both the usual axial grooves and the complementary grooves destined to accommodate a key.
The coupling body is first fixed to one of the two devices, generally the one provided with the driven shaft.
In the case of the motor-pump coupling, it is the pump that is provided with the driven shaft.
The coupling of this type of device, in particular the pump with the respective actuating motor, is done in the prior art with the aid of a coupling body which enables stably coupling the actuating drive shaft of the pump with the shaft of the motor.
The coupling body, which also functions as a spacer, is a hollow body provided at ends thereof with two flanges, of which one is destined to fix the hollow body to the pump body, and the other is destined to fix the hollow body to the motor body.
The coupling body is first fixed to the pump body, and then the pump body together with the coupling body is fixed to the motor body.
The flange destined to couple with the surface of the motor body, from which the drive shaft exits, has at least three holes for receiving fixing bolts, destined to be place in correspondence with a same number of threaded holes present in the motor body.
Suitable bolts are inserted in the holes of the flange and screwed into the corresponding holes of the motor body.
The bolt must be locked with an appropriate torque so as to guarantee the stability of the coupling.
The document U.S. Pat. No. 4,073,606 discloses a mechanical coupling group respectively provided with a drive shaft and a driven shaft, constituted by a coupling body having a hollow cylindrical central portion able to contain coupled ends of the two shafts, and two end flanges of which a first flange destined to couple with the body of the device provided with the driven shaft (13), and a second flange destined to couple with the body of the device provided with the drive shaft, threaded means being provided with a broadened head for fixing each of the two flanges to the body of the respective device.
The known constructions are not without drawbacks.
It is necessary to realise the precise positioning of the coupling body, already fixed to the pump, on the surface of the motor; substantially it is necessary to place the holes of the flange of the coupling body exactly corresponding to the threaded holes present in the motor body.
This is generally obtained by the use of assembly templates.
Once the positioning has been done, the bolts have to be introduced into the holes of the flange of the coupling body and then the bolts are completely screwed and locked in the holes of the motor body.
The operation is laborious as once the bolts are inserted in the holes of the motor body, the complete screwing and blocking thereof is not possible using normal screwing means, due to dimension-related questions.
This implies a considerable amount of time and labour for the operator.
The aim of the present invention is to remedy the drawbacks of the known constructions.